Wheel adjustment means for lawn mowers



Dec. 2, 1958 w. c. WEHNE R 2,862,721

WHEEL AQJUSTMENT MEANS FOR LAWN MOWERS 3 Sheets-Sheet 1 Original Filed April 4, 1955 ENTOR.

Dec. 2, 1958 w. c. WEHNER WHEEL ADJUSTMENT MEANS FOR LAWN MOWERS Original Filed April 4, 1955 5 Sheets-Sheet 2 INVENTOR. Wz/Zwrr/ C lo eZzzer BY K 2 FTfOFA/J/ w. c. WEHNER WHEEL: ADJUSTMENT MEANS FOR LAWN MQWERS Original Filed April 4, 1955 Dec. 2, 1958 3 Sheets-Sheet 3 IN V EN TOR.

BY V

WHEEL ADJUSTMENT MEANS FOR LA MOWERS William Charles Wehner, Grosse Pointe, Mich., assignor,

by mesne assignments, to Mote-Mower, Inc., a corporation of Delaware 7 Original application April 4, 1955, Serial No. 498,997.

Divided and this application April 12, 1957, Serial No. 652,532 i 2 Claims. c1.2s 44 This invention relates to lawn mowers of the rotary blade type and particularly to selflpropelled mowers of this type, and this application is a division of my copending applicationSerial No. 498,997, filed April 4, 1955.

It is the principal object of this invention to 'provide, ina rotary mower, an easily operated device for adjusting the' cutting height of the blade without use of tools and which does not require loosening of bolts, operation of clamps, or the like.

Other objects and advantages of the invention will be Fig. 2 is a longitudinal sectional view taken along line I 22 of Fig. 1;

Fig. 3 is a partial elevation of the mower from the" front with the guard removed;

Fig. 4 is'a partial transverse section taken just forward of the rear body frame member and showing the driving mechanism for therear wheels; e V

Fig. 5 is'at-detailshowingof the frontwheel adjustment means'a's seen when looking-in the direction of the arfows5- -5ofFig.1;- 7 1 a a Fig. 6 is another detail of the wheel adjustment means shown in enlarged detail, the portion shown being indicated by the circle 6 in Fig. 1.

Referring now to the drawings, itmay be seen that the machine comprises a deck or chassis member 10 on which front wheels 12 and rear wheels 14 are mounted. The deck is of welded reinforced construction and carries the engine 16 on the top surface thereof. The engine is preferably of the 4-cycle, internal combustion type although any other suitable engine, electric motor, or the like may be used.

The engine 16 is mounted with its crankshaft vertically disposed. The crankshaft extends above the engine head (Fig. 1) and has a starting pulley 18 on the upper end. If desired, a recoil starter, electric starter, or similar device may be coupled to the shaft at this location. The shaft 16 extends below the bottom of the engine housing, the lower end 20 (Fig. 2) having the cutting blade 22 mounted directly thereon.

As will be seen in Fig. 2, the deck 10 is formed by stamping and has a conically dished portion 24 centrally thereof. Around the upper portion of the cone, a number of engine mounting bosses (not shown) are formed and the engine is rigidly mounted on these bosses. The rear portion of the cone has a depressed portion 26 which, together with a removable cover 28, form an enclosure for the driving belt 30. The belt 30 is trained around the pulleys 32 and 34. The pulley 34 is carried by the input shaft of the multi-speed transmission 36 which will be described later on.

The pulley 32 is mounted on a hub member 38 which is keyed to the shaft 20. -A second hub member 40 carries the cutting blade assembly and has stepped sur-.

faces which interfit with the member 38 and shaft 20 as shown, a cap screw 42 being provided for fastening the parts rigidly together.

The cutting blade 22 is sandwiched between two brass friction washers 44 over a round portion of the hub member 40 followed by a heavy steel D-hole washer 46 which fits over two milled flats. A hex nut 48 is threaded over the lower end of the member 40 and may.

This assembly 7 be tightened to specific desired torque. of the cutting blade permits slippage of the blade on the hub in the event the blade hits an obstruction during use.

A reinforcing steel ring 50 is welded inthe open lower end of the cone 24 andas will be seen from Fig.

2, the ring-50 surrounds a substantial portion of the :hub member 38 With slight radial clearance. This construction is extremely effective in eliminating bending of the engine crankshaft since the shaft end portion 20 can deflect (when the blade 22 encounters an obstacle) only to the extent of the clearance between it and the inner surface of the hub member 38. Bending of the crankshaft sufiiciently to impart a permanent set with subsequent failure thereof is thus entirely avoided.

Referring now particularly to Figs. 1 to 6 inclusive, it may be seen that the rear propelling wheels 14 are driven from the transmission gearbox 36 by means of axle shafts 52. Each of the driving wheels comprises a casting having an integrally formed internal gear 54 and an integrally formed rim '56 on which is mounted a rubber tire 58.

The hub 60 of each wheel is rotatably carried on a stub' axle 62 which is, in turn, carried by a plate assembly 64. The latter is secured to the deck structure by the bolts 66 which'thread'edly engage the weld nuts 68 fixed pressed when the wheel mounting screw 74 is. tightened. A hub cap 76 snapsinto placeover the end of the screw 74 to protect the hub and present aneat ap pearance.

The internal gear 54 is engaged bya pinion 78 carried:

on the outer end'of theaxle shaft 52' and driven from the shaft through a conventional differential pawl which provides a one-way only drive'to the wheel. A spider 82 secured to the plate 70 seals the assembly against entry of dirt or water which might adversely affect quiet operation of the gear and pinion drive. The shaft 52 is self-aligning and is supported near its outer end by a bushing 84 carried by the plate 70.

The gearbox 36 is carried on a plate 86 which is suspended from the deck of the machine by a vertically disposed plate 88. The front deck cover extends downwardly and the plate 86 is suitably fastened thereto, thereby providing a rigid support for the gearbox.

The mower is guided by a handle assembly which is free-floating for eliminating shock transmission to the hands of the operator when mowing over rough terrain. The handle assembly is divided into two sub-assemblies for convenience in shipping. The lower sub-assembly consists of a inch tube formed into an arch with each leg thereof pivotally attached to the rear portion of the deck 10 (see Fig. 2). The upper sub-assembly (not shown) comprises a pair of inch tubes bent outwardly at their upper ends on which handle grips are placed.

Attention is now directed to Figs. l-6 inclusive, for a description of the means for adjusting the depth of cut of the mower.

The front wheel mounting comprises a pair of stamped ball races 190, 192,'concentrically mounted. The outer race 192 has a stub axle 194 welded thereon one inch from the center of the race. The inner race is welded Patented Dec. 2, 1958 I which the lever. 208 is'engaged.

that because of the eccentric mountingofthe axle-194- on-the outer race 192, rotation of that race around the to the vertical side portion of the front section 196 of the deck 10. The races are secured in-assembled relation by a carriage bolt 198, a plurality of balls 200 being disposed .between the races in grooves 204, 206, formed thereinby stamping. A combined retainer; and-seal 202 of brass or similar material retains the balls in properly I spaced relation and .prevents. entry of foreign matter. 1

A lever 208"of spring steel is mounted 'on-the-bolt-198,

alongwith the outerrace 192, andengages a slot 210 in the outer race 192. The inner race 190-is provided with a series of slots 212;preferably five or more, in one of Thefront wheels 12 are constructed of two identical stampings, welded together along a circumferential line mediallyiintermediate the hub and rim portions as illustrated in Fig. 1, theouter marginal portions being fiaredand bent over. toform a rim adapted to mount a rubber tire.

' As' maybe seen from Figs. 1, 2, 5 and 11, the deck It will now be clear stamping 10*has skirts at the sides thereof which extend below the plane of the, cutting blade22 for safety. The

right hand skirt isprovided with a discharge chute 216 which permits discharge of grass cuttings (and leaf mulch when a mulching attachment is used) to one side of the machine. The deck stamping is open at .the front such that the blade 22extends forwardly of the deck between the front wheels 12. This permits cutting of tall grass, weeds, etc., which could not be cut ifthe blade did not extend beyond the front end of the deck. A removable cover-214 is suitably fastened to the deck during all ordinary operation of the mower, the cover extending downwardly sufficiently to cover the blade and prevent accidents,

I claim:

1. In a lawn mower or the like, the combination of a deck having a horizontal portion and depending skirt portions, means mounting a ground eangging wheel on said deck comprising a fixed plate secured to one of said skirt portions and having an outwardly facing annular ball race formed-therein,- a marginalfiange carried by said fixed plate having radial'slots therein, a second plate rotatably secured to said fixed plate and having an inwardlyfacing annular ball race formed therein, a plurality of balls disposed in said races, a spring lever carried by said second plate and adapted to be engaged with. one or another of said radial slots for rotatively positioning .saidsecond plate in selected position, and a wheel-axle eccentrically mounted on said secondplate.

2. In a lawn mower or the like, the combination of a deck having a horizontal portion and depending skirt portions, means mounting a ground engaging wheel on said deck comprisinga fixed plate secured to one of said skirt portions and having. an outwardly facing annular ball race formed therein, a marginal flange carried by said fixed plate having radial slots therein, a secondplate rotatably secured to said fixed plate and having an inwardly'facing' annular ball race formed therein, a plurality-of balls disposed in said races,'a spring lever carried by said second plate and adapted to be engaged with.

one ,or another of said radial slots for rotatively positioning saidjsecond plate in selected position, a wheel-axle eccentricallymounted on said second plate, an annular member disposed between said' plates having holes for loosely holding said balls in spaced relation, said member having an annular marginal portion engaging said second plate radially outwardly of said balls and an annular flanged portion engaging said fixed plate radially outwardly ofsaid balls whereby said assembly is sealed against entry of foreign matter.

References Cited in the file of this patent UNITED'STATES PATENTS 473,816 Binns Apr. 26,1892; 706,209 Sumner ...V Aug. ,5, 1902 1,304,783 Lederer V May 27, 1919 1,880,915 Dyer Oct., 4,. 19321. 

